Wretched Bonemass

Wretched Bonemass's power and toughness are each equal to the total power of the exiled cards used to craft it.
Wretched Bonemass has flying as long as an exiled card used to craft it has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, and vigilance.

Altar of the Wretched

When Altar of the Wretched enters, you may sacrifice a nontoken creature. If you do, draw X cards, then mill X cards, where X is that creature's power.
Craft with one or more creatures {2}{B}{B}
{2}{B}: Return Altar of the Wretched from your graveyard to your hand.

Altar of the Wretched // Wretched Bonemass

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Acid-Spewer Dragon

Flying, deathtouch
Megamorph {5}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Acid-Spewer Dragon is turned face up, put a +1/+1 counter on each other Dragon creature you control.

Wilson, Refined Grizzly

This spell can't be countered.
Vigilance, reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Choose a Background (You can have a Background as a second commander.)

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Eater of Virtue

Whenever equipped creature dies, exile it.
Equipped creature gets +2/+0.
As long as a card exiled with Eater of Virtue has flying, equipped creature has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, and vigilance.
Equip {1}

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Lórien Revealed

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Simic Locket

{T}: Add {G} or {U}.
{G/U}{G/U}{G/U}{G/U}, {T}, Sacrifice Simic Locket: Draw two cards.

Command Tower

Bontu the Glorified

Menace, indestructible
Bontu the Glorified can't attack or block unless a creature died under your control this turn.
{1}{B}, Sacrifice another creature: Scry 1. Each opponent loses 1 life and you gain 1 life.

Satyr Wayfinder

When Satyr Wayfinder enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Bane's Contingency

Counter target spell. If that spell targets a commander you control, instead counter that spell, scry 2, then draw a card.

Simic Cluestone

{T}: Add {G} or {U}.
{G}{U}, {T}, Sacrifice Simic Cluestone: Draw a card.

Bloodvial Purveyor

Flying, trample
Whenever an opponent casts a spell, that player creates a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever Bloodvial Purveyor attacks, it gets +1/+0 until end of turn for each Blood token defending player controls.

Llanowar Elves

Bassara Tower Archer

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Kefnet the Mindful

Flying, indestructible
Kefnet the Mindful can't attack or block unless you have seven or more cards in hand.
{3}{U}: Draw a card, then you may return a land you control to its owner's hand.

Scavenged Brawler

Flying, vigilance, trample, lifelink
{5}, Exile Scavenged Brawler from your graveyard: Choose target creature. Put four +1/+1 counters, a flying counter, a vigilance counter, a trample counter, and a lifelink counter on that creature. Activate only as a sorcery.

Temple of the Dead

(Transforms from Aclazotz, Deepest Betrayal.)
{T}: Add {B}.
{2}{B}, {T}: Transform Temple of the Dead. Activate only if a player has one or fewer cards in hand and only as a sorcery.

Aclazotz, Deepest Betrayal

Flying, lifelink
Whenever Aclazotz attacks, each opponent discards a card. For each opponent who can't, you draw a card.
Whenever an opponent discards a land card, create a 1/1 black Bat creature token with flying.
When Aclazotz dies, return it to the battlefield tapped and transformed under its owner's control.

Aclazotz, Deepest Betrayal // Temple of the Dead

Venomthrope

Mwonvuli Beast Tracker

When Mwonvuli Beast Tracker enters, search your library for a creature card with deathtouch, hexproof, reach, or trample and reveal it. Shuffle and put that card on top.

Dark Ritual

Sphinx of the Final Word

This spell can't be countered.
Flying, hexproof
Instant and sorcery spells you control can't be countered.

Nightveil Predator

Flying, deathtouch
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Abundant Growth

Enchant land
When Abundant Growth enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Admiral's Order

Raid — If you attacked this turn, you may pay {U} rather than pay this spell's mana cost.
Counter target spell.

Censor

Counter target spell unless its controller pays {1}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Dimir Cluestone

{T}: Add {U} or {B}.
{U}{B}, {T}, Sacrifice Dimir Cluestone: Draw a card.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Infernal Sovereign

Flying, trample
Skip your draw step.
Whenever you play a land or cast a spell, you draw a card and you lose 1 life.

Dimir Locket

{T}: Add {U} or {B}.
{U/B}{U/B}{U/B}{U/B}, {T}, Sacrifice Dimir Locket: Draw two cards.

Island

Vampire of the Dire Moon

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Tapping at the Window

Look at the top three cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest into your graveyard.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Simic Signet

Dimir Signet

Majestic Myriarch

Majestic Myriarch's power and toughness are each equal to twice the number of creatures you control.
At the beginning of each combat, Majestic Myriarch gains flying until end of turn if you control a creature with flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Adventure Awaits

Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. If you didn't put a card into your hand this way, draw a card.

Selective Adaptation

Reveal the top seven cards of your library. Choose from among them a card with flying, a card with first strike, and so on for double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance. Put one of the chosen cards onto the battlefield, the other chosen cards into your hand, and the rest into your graveyard.

Soulflayer

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
If a creature card with flying was exiled with Soulflayer's delve ability, Soulflayer has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, reach, trample, and vigilance.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Forest

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Indominus Rex, Alpha

As Indominus Rex, Alpha enters, discard any number of creature cards. It enters with a flying counter on it if a card discarded this way has flying. The same is true for first strike, double strike, deathtouch, hexproof, haste, indestructible, lifelink, menace, reach, trample, and vigilance.
When Indominus Rex enters, draw a card for each counter on it.

Abyssal Persecutor

Flying, trample
You can't win the game and your opponents can't lose the game.

Cairn Wanderer

Changeling (This card is every creature type.)
As long as a creature card with flying is in a graveyard, Cairn Wanderer has flying. The same is true for fear, first strike, double strike, deathtouch, haste, landwalk, lifelink, protection, reach, trample, shroud, and vigilance.

Lunar Hatchling

Flying, trample
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)
Escape—{4}{G}{U}, Exile a land you control, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Vampire Nighthawk

Counterspell

Swamp

Nullpriest of Oblivion

Kicker {3}{B}
Menace, lifelink
When Nullpriest of Oblivion enters, if it was kicked, return target creature card from your graveyard to the battlefield.